DIY Doctor UK DIY Forums

Last September, with help from a few gents on here, I wired an old horse trailer to be used as a Gin bar. All has worked okay, until a couple of weeks ago. One of the 16A MCB's that I fitted in a 'Garage consumer Unit' is found to be in the off position. Even if there is no power attached to the trailer, the MCB can be found in the off position. I have not yet had a look at the trailer, I am just going off a phone call from my son, who owns and runs it. Is it possible for an MCB to have a fault that could cause it to flick off even though no power is going through it? He told me it first happened a couple of weeks ago when there was a mains cable attached to the trailer. He normally runs if from a generator. I have a spare 32A MCB that came with the unit, that I can try, but just wondered, before I start pulling all the sockets apart, if a faulty one is possible?

Changing a 16A mcb to a 32A mcb is not a good idea.
MCB's by design need a supply to operate, they do not "trip" on their own. But that said, you can always physically switch one off.

Thanks Mr White.
I realise that a 32A is not a good idea, that is why I fitted the 16A in the first place. I know that in theory they should not 'trip' on their own. That is why I was asking if anybody had any idea whether it was possible, Faulty whatever, that holds the switch in the on position? If there is no electric going through it, how on earth is it switching. I will have to go and search through all the connections and see what I can find. I thought I could just fit another MCB and see if that switched off on its own. Whilst writing this I just remembered I may have a 6A MCB that I took out when I swapped the sizes over. The Unit came with a 6A and a 32A, and I fitted two 16A